Trap Catches to July 24, 2026.

Aphid vector numbers remain behind those of last year as does the PY Vector Risk Index. Average capture per trap was similar to that of the previous week (1.7 vectors/trap vs 2.2 vectors/trap last week) but the total number of vectors captured across the region has increased slightly. This reflects aphids being captured at more locations, albeit still at low numbers. 

Soybean aphids remain relatively common, being collected at most locations. Small grain aphids are beginning to become more common and Buckthorn aphids remain steady.

Expect more small grain aphids as the season progresses. While the return of high temperatures during the day may decrease reproduction rates, our night temperatures will be within good reproduction temperatures.

While trap numbers are low, aphid vectors are flying. Use appropriate management tactics.

Keep on Scouting.

 The usual reminders:

- vector flights have started, so start scouting; aphids can establish early after potatoes are up. Field scouting is less effective at finding aphd vector species that don't colonize potatoes. While these species will enter potato fields and probe plants, they cannot survive on potatoes. Consequently, they'll keep moving through the field, sampling more plants and potentially moving inoculum already in the field to uninfected plants. Consult risk assesment sites (like this one) and check weather-based predicitve models like University of Wisconsin's Vegetable Disease & Insect Forecasting site (https://agweather.cals.wisc.edu/vdifn).

- the research literature reports that the use of crop oils is the most consistent post-planting technique in preventing transmission of PVY and it can be improved with the addition of the insecticide Lambda-Cyhalothrin.

- most of the research indicates that insecticides on their own are not effective enough at suppressing PVY transmission, but are still useful parts of your management program. Treating fields with one of the anti-feeding insecticides such as Sivanto Prime, Sefina or Transform to control colonizing aphids, such as green peach, potato, or cotton melon aphids, can be beneficial

- if using a border crop, it's a good idea to use treated seed to prevent the development of potential vector species in that border.

Have a great week and keep on scouting!

Click on any image below for full-scale version.

Cumulative PVY Risk Index by Site to 7/24/2026

For Comparison, Cumulative PVY Risk Index by Site to 7/25/2025 

Aphid Species Capture and PVY Vector Risk Index for the week ending 7/24/2026

Cumulative Aphid Species Capture and PVY Vector Risk Index to 7/24/2026